This invention relates to a serpentine food processor and method such as for use in processing meat products, and more particularly to circulation of air or other processing medium within the food processor.
Various serpentine food processors are known in the art, such as shown in U.S. Pat. Nos. 4,784,053, 4,329,850, 4,277,954, 4,138,860, the disclosures of which are hereby incorporated by reference.
A serpentine food processor typically employs a continuous serpentine chain conveyor for transporting the food product through a processing chamber. The chamber has a predetermined temperature and environment for processing the food product, such as for cooking or chilling the product. The serpentine path provides a plurality of parallel flights connected at their ends by U-shaped bends. Each piece of food product carried by the serpentine conveyor is exposed to the same conditions of cooking or chilling as the piece of product ahead of or behind it. This provides a high degree of product uniformity, which results in high yields and extended shelf life of the product.
In the processing chamber, cooking heat may be provided by steam, hot water, hot air or the like, and chilling may be provided by a tap water shower, recirculated brine or glycol, cooled air or the like.
Prior art serpentine systems employ ducts on either side of the processing chamber or compartment which are supplied with heat or cooled air or other processing medium, which is discharged downwardly through nozzles in communication with the ducts for introducing the processing medium into the interior of the compartment. The nozzles are located on either side of the compartment, so as to force the processing medium downwardly to the bottom of the compartment, after which the medium passes through the compartment so as to expose the product thereto. The processing medium is then exhausted through a flue mounted to the top of the compartment.
In the type of system described, the internal width of the chamber compartment must be sufficient to accommodate the discharge nozzles and to provide a flow path for downward flow of the medium to the bottom of the compartment, whereafter the medium diffuses upwardly through the product prior to being exhausted. Additionally, the overall exterior width of the processing system includes the duct work. This provides an overall package which is quite wide, and which can be installed only in an area having sufficient room to accommodate such width.
Further, it has been found that the circulation of air or other processing medium downwardly along the sides of the compartment and upwardly through the product can result in nonuniformity of the product across the width of the product carriers.
The invention of the above noted parent application has as its object to address the concerns noted above by providing a serpentine food processor having a decreased width and which also provides improved circulation of the processing medium through the compartment and over the product therein, resulting in an increase in product uniformity.
In accordance with the parent invention, a food processing system comprises a processing chamber or compartment and a continuous conveyor for transporting the food product through the compartment along a serpentine path. The system further includes means for supplying a processing medium to the compartment and for providing movement of the processing medium through the compartment in a one-way vertical path throughout the entire width of the compartment for the full height of the serpentine path. In one embodiment, the processing medium supply means comprises a supply outlet located above the uppermost point of the serpentine path for outletting the processing medium above the conveyor, and collection means located below the lowermost point of the serpentine path for collecting the processing medium after it passes through the serpentine path. This arrangement provides top-to-bottom vertical one-way flow of the processing medium through the serpentine path. The processing medium supply outlet preferably comprises a supply plenum located in the uppermost portion of the compartment, with the supply plenum receiving the processing medium under pressure from a supply duct having an outlet in communication with the interior of the supply plenum.
In accordance with another aspect of the parent invention, recirculation means is provided for recirculating the processing medium after discharge thereof from the processing compartment. In the embodiment providing top-to-bottom flow of the processing medium through the serpentine path, the recirculation means comprises a blower having its intake in communication with the collection means and having its outlet in communication with the processing medium supply outlet. When the processing medium is heated, a burner or the like is provided for reheating the processing medium before it is resupplied to the processing compartment.
In the present invention, the processing medium is provided to the chamber and is recirculated along a closed-loop unidirectional recirculation path having a supply path portion along and parallel to a first set of flights of the serpentine conveyor path, and a return path portion along and parallel to a second set of flights. A blower has a high pressure supply side supplying the processing medium to the supply path portion, and a low pressure return side drawing the processing medium from the return path portion. The processing medium acts on the food product in both the supply and return path portions, and the food product on the flights travels both with and against the direction of flow of the processing medium during each of the supply and return path portions without reversing the direction of flow of the processing medium along the closed-loop recirculation path.